Beta blockers

Drugs that belong to this group of substances are used to treat the main cardiac pathology: coronary heart disease (including acute myocardial infarction, angina pectoris prophylaxis), arterial hypertension, tachyarrhythmia, chronic heart failure.

Beta adrenoblockers perform the function of competitive antagonists of norepinephrine, adrenaline and other substances that have the properties of beta adrenomimetics on adrenoreceptors.

The effectiveness of the application of substances of this group directly depends on the state of the sympathetic nervous system. With the increase in the work of this system, substances work more effectively on the human body. And vice versa. In particular, their effectiveness increases with various pathologies of the heart, which are accompanied by stressful conditions, thyrotoxicosis, in smokers (nicotine increases sympathetic tone).

Medicinal substances of this pharmacological group are divided into three types: mixed, non-selective and selective. Beta adrenoblockers: atenolol, metoprolol, acebutolol, bisoprolol, esmolol - are of the third type. Non-selective drugs are represented by propranolol, nadolol, pindolol, penbutalol, timolol, oxprenolol, sotalol. Blended adrenoblockers: labetalol, carvedilol.

Application

The main cardiac pathology, in which beta adrenoblockers are used, is ischemic heart disease. The mechanism of action of substances is the blockade of beta adrenoreceptors, which leads to a decrease in all functions of the heart: contractility, conduction, excitability, automatism. The result is a decrease in heart function, which is manifested in a decrease in the frequency of heart contractions, stroke volume and cardiac output. The need for myocardium in oxygen is significantly reduced, and thus provides effective prevention of angina attacks. Drugs in this group reduce the risk of sudden death in patients who have suffered myocardial infarction.

Beta-blockers are also used to stop tachyarrhythmia. Reduction of the frequency of cardiac contractions, retardation of atrial-ventricular conduction explains this therapeutic effect. More pronounced effect of drugs is observed in the presence of atrial arrhythmias.

Medicinal substances that have a beta blocking effect belong to one of five classes of antihypertensive substances. They are used to treat any stage of arterial hypertension, as well as to treat the symptomatic type of the disease. The mechanism of action of beta adrenoblockers consists of four components: a decrease in heart function, suppression of the renin-angiotensin system, a decrease in the tone of the vasomotor center, a decrease in the total peripheral resistance of the blood.

Adrenoblockers are used to treat chronic heart failure. Preparations of this group remove the excessive influence of the sympathetic nervous system on the heart. This reduces the adverse effects of adrenaline and norepinephrine on the heart, decreases the activity of beta adrenoreceptors, slows the frequency of cardiac contractions. However, the use of excessive doses of these drugs can make heart failure worse.

Beta blockers are also effectively used to treat open-angle glaucoma. They help to reduce the secretion of the fluid of the ciliary body. Thus, intraocular pressure decreases, and the symptoms disappear.

For the treatment of migraine attacks, metoprolol, atenolol, timolol and nadolol are used. Their action is explained by spasm of cerebral vessels, agonistic activity of drugs to serotonin receptors in the central nervous system.